Saborage-resistant switch device for moving railroad switch points

Abstract

The switch machine disclosed uses electro-hydraulic power to move the throw rod against the resistance of redundant mechanical springs and the switch point, for half of its stroke. Once the switch points have moved past mid-stroke the spring force in the machine is released and assists in the closure of the switch points against the stock rail. All hydraulic force is removed when the power unit is turned off. The redundant spring assembly holds the switch points firmly against the stock rail with 2000 lbs of holding force. This machine can be described as a power operated spring switch.

What is claimed is: 
     
       1. A railroad switch device for moving railroad switch points, the railroad switch device comprising:
 a hydraulic power unit comprising:
 a hydraulic manifold, wherein the hydraulic manifold is adapted to move fluid as needed to activate movement of a first switch operation unit and a second switch operation unit as directed by a control system, wherein the first switch operation unit comprises a first spring unit and the second switch operation unit comprises a second spring unit, where each spring unit has two springs, wherein the two spring units produce a continuous thrust force for holding the railroad switch points closed in forward position and reverse position; and 
 a hydraulic cylinder to provide forward movement and reverse movement for the railroad switch points,
 wherein the hydraulic manifold, and the hydraulic cylinder are fluidly coupled to define a hydraulic circuit, wherein the hydraulic circuit controls an operation period of the railroad switch device, and 
 wherein the hydraulic power unit is coupled to a first point rod position indicator and a second point rod position indicator, 
 
 
 at least one first proximity sensor to detect a point rod position for a first point rod; 
 at least one second proximity sensor to detect a point rod position for a second point rod; and 
 a power unit to supply the hydraulic power to the hydraulic power unit for moving the first point rod and the second point rod, wherein the first point rod and the second point rod provide forward movement and reverse movement to define an operation cycle in the railroad switch device. 
 
     
     
       2. The railroad switch device according to  claim 1 , wherein the two spring units provide a combined 3200 lbs of constant holding force against a stock rail. 
     
     
       3. The railroad switch device according to  claim 1 , wherein the first spring unit and the second spring unit independently provide a holding force for the railroad switch points. 
     
     
       4. The railroad switch device according to  claim 1  wherein the power unit is at least one of a DC battery source, an AC power source, or combination thereof. 
     
     
       5. The railroad switch device according to  claim 1  wherein the control system is one of a programmable logic controller (PLC) and a digital computer, wherein the control system is used to control and monitor input signals from the at least one first proximity sensor and the at least one second proximity sensor and report events and conditions occurring in a controlled process of the railroad switch device. 
     
     
       6. The railroad switch device according to  claim 1 , wherein the hydraulic power is turned off and the railroad switch points are kept closed by a spring force upon detecting the first point rod and the second point rod move to the railroad switch points from one position to another. 
     
     
       7. A method of handling an operation of railroad switch points, comprising:
 activating movement of a first switch operation unit and a second switch operation unit as directed by a control system and a hydraulic manifold, wherein the first switch operation unit comprises a first spring unit and the second switch operation unit comprises a second spring unit, where each spring unit has two springs; 
 producing a continuous thrust force for holding the railroad switch points closed in forward position and reverse position using the two spring units; 
 detecting a point rod position for a first point rod using at least one first proximity sensor; 
 detecting a point rod position for a second point rod using at least one second proximity sensor, wherein the at least one first proximity sensor and the at least one second proximity sensor are coupled with the first switch operation unit and the second switch operation unit respectively; and 
 supplying a hydraulic power to a hydraulic power unit from a power unit for moving the first point rod and the second point rod, wherein the first point rod and the second point rod provide forward movement and reverse movement to define an operation cycle in the railroad switch device.